1. Field of the Invention
The present invention relates to a chip, and more especially, to a chip with an adjustable pinout function and a method thereof.
2. Description of the Prior Art
A printed circuit board (PCB) generally has several chips and several passive devices thereon. Because most electronic products using PCBs tend to be shrunk in volume, the layout and wiring of devices on the PCBs become more and more important for shrinking purposes. Practically, the wiring on the PCB is designed as short as possible such that the area of the PCB is minimized and the interference among the wirings or from outside the PCB is reduced. As a result, the layout and wiring of devices on the PCB must be implemented in correspondence to the pinout definitions of the chip adopted on the PCB. Therefore, the devices are set on proper positions of the PCB. Please refer to FIG. 1. The PCB 100 has chips 110, 120, and 130 positioned thereon. It is assumed that the pins on the side A of the chip 110 have connection relationships with the pins on the side A′ of the chip 120, and that the pins on the side B of the chip 110 have connection relationships with the pins on the side B′ of the chip 130. Therefore, the connection relationships between pins of chips 110, 120, and 130 constrain the placement of chips 110, 120, and 130 on the PCB for the sake of minimizing the area of the PCB and shortening the wirings. For this purpose, an exemplary layout of the chips 110, 120, and 130 is shown in FIG. 1. If the chip 120 is moved above the chip 110 on the PCB 200, as shown in FIG. 2, the length of the wirings is increased, leading to high cost, large PCB area, and undesirable interference.
In short, during manufacturing of a prior art PCB, the pinout definitions of chips constrain the layout of PCB and greatly affect the length of wirings. If the pinout definitions of chips were less limiting, the layout of the PCB would become more flexible.